The present invention relates to a bicycle having dual-purpose pedals and, more particularly, to a bicycle whose pedals having both a conventional 360-degree circular rotation pedaling function and a special same-up-same-down pedaling function.
Bicycle use has evolved from transportation to leisure activity. Bicycles as a recreational activity do not require fuel, create no pollution, are conveniently portable, and good for the health and thus are very popular. The bicycle market is accordingly lucrative and the object of great interest, and research is continually conducted to improve the basic structure and function of bicycles. However, to date, research has only improved the speed, material, shape and comfort of bicycle but seldom accessed the function and amusement of bicycle. Therefore, existent bicycles have only a conventional 360-degree circular rotation pedaling function, which is monotonous and invariant, and a rider may become bored.
The primary object of the present invention is to provide a bicycle having dual-purpose pedals. Through the unique design of an axis and a crank of the pedal of the bicycle, the bicycle can be used as a conventional bicycle having a conventional one-up-one-down, 360-degree, circular oration pedaling function. The user can also change and control the two pedals to accomplish a special same-up-same-down pedaling function so that the bicycle may be ridden forwards like riding on a horse. The bicycle can thus be ridden in two ways, hence enhancing the entertainment thereof.
To achieve the above objects, the present invention provides a bicycle having dual-purpose pedals, in which the structure in a main shaft tube thereof is improved. The structure comprises a main shaft, a first spring, a gear bushing, a crank, a second spring, a washer and a fixing unit. The main shaft is received in the main shaft tube. Two ends of the main shaft are bearing portions. The outer diameter of one of the bearing portions diminishes and is horizontally extended to a fixing gear to form a gear portion. The outer diameter of the gear portion also diminishes and is horizontally extended to form a fixing portion. The first spring is telescoped onto the main shaft. One end of the first spring away from the gear portion is fixedly arranged on the main shaft. The other end thereof has a circular hole pressed onto the main shaft. The gear bushing is telescoped onto the fixing portion of the main shaft and correspondingly engages the gear portion. The outside of the gear bushing has two corresponding grooves. One end of the crank has a crank hole. A flange is disposed on the outside of the crank hole. Two corresponding projective bars are disposed in the crank hole. The projective bars are matched with the two grooves of the gear bushing. The second spring is received in the crank hole and abuts the gear busing. The washer abuts the flange of the crank hole and the second spring. A screw passes through the washer and is fixedly locked into the fixing portion of the main shaft to position the crank on the main shaft. A pin of the fixing unit passes through a through hole of the main shaft tube and is fixed in a position on the main shaft tube corresponding to the circular hole of the first spring.
When a user holds the left pedal steady with his left foot and moves the right pedal forward 180 degrees with his right foot, the engagement between the gear bushing and the gear portion of the main shaft is exploited to let the two pedals of the bicycle be at the same height and move in the same direction. The user then presses down the fixing unit to block the circular hole of the first spring so as to fix the first spring on the main shaft tube. At this time, the user can step on the two pedals to drive the bicycle to advance in a same-up-same-down way. On the other hand, if the user moves the right pedal forward 180 degrees with his right foot and releases the fixing unit, he can restores the two pedals to the conventional, 360-degree, circular rotation, one-up-one-down pedaling function.